Vacuum pump



July 1,9, 1932. T F MOORE 1,867,585

VACUUM PUMP T. F. MOORE July 19, 1932.

VACUUM PUMP Filed Feb. 16, 1931 2 Sheets-Sheet /nvENToR r f er/YAoxn/Evs 'In/rNE ss Patented July 19, 1932 UNTED SFTES THOMAS F.MOOR-E, OF MOR-RIS PLAINS, NEW JERSEY VACUUM PUMP Application filedFebruary 16, 1931. Serial No. 516,057.

rlhis invention relates to a vacuum Ypump adapted to be used moreparticularly for withdrawing air from centrifugal hydraulic pumps orfrom the standpipes used in connection therewith, set forth in myvpending application, Serial No. 380,223, filed July 22, 1929, to reducethe liability of the centrifugal pump becoming airbound, but obviouslythe same vacuum pump may be used in many e other relations.

The vacuum pump is adapted to be mounted upon or in close proximity tothe supporting base for the centrifugal pump in such manner that one andthe same shaft may be used as the primary driving means for the impellerand for the piston of the vacuum pump whereby both pumps may be readilytransported as a unit from place to place for use more particularly forwithdrawing zo Water from the soil preparatory to excavations forsuperstructures.

`The main object, therefore, of the present invention is to provide asimple, compact and highly efficient vacuum pump which may be easily andquickly applied to the shaft of a centrifugal pump or to an extensionthereof so that the two pumps may lie in contiguous relation, thuspermitting both pumps to be operated by one and the same power unit sowhen desired, such, for example, as an electric motor.

Another object is to drive the piston of the vacuum pump through themedium of a power multiplying and speed reducing gear train andincidentally to conserve the power required for operating the vacuumpump and at the same time adapt the speed of operation thereof to therequirements of the centrifugal pump.

Another object is to arrange the gears of the train with their axes inone and the same plane and to divide the gear case along the same planeso that one section thereof may be readily removed for repairs orreplacements of the gears as may be required to vary the speed ofoperation on the vacuum pump to suit the requirements ofthe centrifugalpump with which it is associated.

A further object is to mount the low-speed gear of the train upon acrank shaft having eti) its axis intersecting the axis of the pistoncylinder and to connect said low-speed shaft to the piston through themedium of a pitman to produce what may be termed a straight-line actionof the driving means for l the piston. f I

Another object is to make the cylinder for the piston separate from thegear case and to provide releasable means for securing those partstogether end to end so as to permit @o either part to be removedindependently of the other part for repairs or replacements whendesired.

Another object is to provide the cylinder with a system of air passagesthrough which the air is circulated by the action of the piston and alsoto provide a system of valves controlled by the circulation of air forcontrolling the air intake and air exhaust to and 1 from thepistonchamber of the cylinder. 79

Other objects and uses relating to specific parts of the vacuum pumpwill be brought'out in the following description.

In the drawings p Figure l is a longitudinal vertical sec- I5 tionalview of a-vacuum pump embodying the various features of my invention.

Figures 2 and 3 are sectional views taken respectively -in the planes oflines 2 2 and 3 3, Figure 1.

As illustrated this vacuumpump is rigidly mounted in a'substantiallyhorizontal position upon a suitable supporting, frame A and comprises agear-case section 1 and a cylinder section 2 secured together end 85 toend byreleasable means, as bolts 3 for rigidly holdin the sections infixed-relation, the frame being located as nearly as possibl-e at ordirectly under the center of gravity ofthe pump for balancing the 90same and reducing to a minimum the vibration incidental to the operationof. the moving parts thereof.

The endrof the gear-case 1 adjacent the cylinder section 2 is providedwith 95 an opening 4 which is normally closed by a transverse partition5 forming the adjacent end of the cylinder section and having a centralgland 6 for receiving the piston-rod of the pump, presently described,to

said gear-case being adapted to receive and retain a quantity of oil forlubricating the gears and other moving parts therein.

The cylinder section -2- is provided with a piston chamber -7 having acircular peripheral wall -8 and outer and inner walls -9- and -10-, thelatter being arranged in axially spaced relation a distancecorresponding approximately to the stroke of the piston.

The end wall -10- ofthe piston chamber is arranged in spaced relation tothe transverse partition -5- to form an intervening space and isprovided with a gland -11- co-axial with the cylinder for receiving andguiding the piston rod.

A piston 12- is reciprocallyv movable endwise within the piston chamber-7- and is provided with a piston rod 13- extending through the glands-11- and -6- into the interior of the gear case section -1-, the innerend of said rod being secured to a cross-head 14- which, in turn, ismovable along and upon suitable guideways 15- as shown more clearly inFigure l.

These guideways are rigidly secured to and are preferably formedintegral with the transverse partition -5- to extend therefrom into thegear case w-1- a distance corresponding approximately to the stroke ofthe piston for guiding the cross-head and piston in their rectilinearmovements.

The inner end of the piston rod -13- is threaded and engaged in athreaded aperture in the adj acent end of the cross-head -14- and isalso engaged by a lock nut l5- for holding the cross-head and piston rodagainst accident-al displacement one from the other.

rlhe guideways l5- form a part of the cylinder section -2- but arelocated within the gear-case so that they, together with the cross head14- and pit-man connection therewith, may be lubricated by theoil-splash from the gears and other moving parts of the piston-actuatingmeans.

The other end of the cross-head lllis provided with a central chamber-16- for receiving the adjacent end of a pitman #17- and a transversepivotal pin -18- by which the pitman is pivotallfy connected to thecross-head with its axis intersecting the axis of the rod as shown inFigure 1. Y

The other end of the pitman -17-' is ournaled upon a wrist pin -19-forming a part of a crank shaft -20-v which in turn is journaled in theopposite upright side walls of the gear case 1- to rotate about an axisintersecting the axis of the piston chamber -7- and piston rod -13, saidwrist pin being counterbalanced by a weight -21- forming a part of thecrank arm as QOL- of the crank shaft, it being understood that the crankshaft 20- is arranged some distance from the inner end of the guideways-15- at right angles to the axis of the piston rod -13- and parallelwith the connecting pin *18- between the pitman 17- and cross-head J4- Aprimary drive shaft -22- is journaled in suitable bearings in one orboth sides of the gear case l-- in a plane some distance above theguideways -15- and also some distance from the crank shaft -20-.

The drive shaft -22- may be an extension of, or co-axial with, theimpeller shaft of a centrifugal pump, not shown, so that both shafts maybe operated simultaneously at the same rate of speed by a single powerunit, such, for example, as an electric motor.

Suitable means is provided for transmitting rotary motion from the driveshaft 22- to the crank shaft -20-, said means consisting, in thisinstance, of a speed reducing and power increasing gear train comprisinga drivingpinion -23- tight on the drive shaft and meshing with anintermediate gear 24- which is secured to a co-axial pinion -25- so thatboth may rotate upon a supporting stud or shaft -26-, the pinion -25-meshing with a relatively larger gear -27- which is secured to the crankshaft -20-.

The axes of the shafts -20-, -26- and -22- are disposed in one and thesame plane diagonal to the axis of the cylinder or, at an acute angle tosaid axis as shown in Figure 1.

The gear case -1- is divided in about the same plane as the axes of theshafts -20-, 26 and *22- and therefore diagonal to the axis of thecylinder to form lower and upper sections -28- and -29-- The uppersection -29- is removable and constitutes what may be termed a capsection to permit access to the interior mechanism and particularly toallow the gears to be removed or replaced for repairs or for changingthe speed ratio of the gear train between the driving shaft 22- andcrank shaft 20- as maybe desired to adapt the vacuum pump to varyingsizes or capacities of the centrifugal pump with which the vacuum pumpis associated, it being understood that portions of the bearings for theshafts Q2- -26- and -20- will be formed in the meeting edges of the gearcase sections Q8- and Q9-, which latter may be secured by any suitablereleasing means, such as bolts, to the adjacent portions ofthe lowersecti on -28* to form a liquid tight joint therein so that the entiregear case may receive and retain a sufficient quantity of oil forlubricating the various moving parts therein and thereby to reduce thenoise incidental to the operation of those parts.

Y Air circulation control The cylinder section -2- is provided withseparate diametrically opposite air chambers -30- and -;3larrangedrespectively above and below the piston chamber -7-, the central outerportion of the chamber being cylindrical and reduced in diameter andconnected by a pipe 32- to the interior of a centrifugal pump orstandpipe leading thereto, not shown, or to any other apparatus fromwhich air is to be withdrawn.

The chamber -80- constitutes what may be termed the air intake chamberand therefore the conduit -32 leading thereto may `be termed the airintake pipe or conduit which is arranged substantially midway betweenopposite ends .of the piston chamber 7 and extends axially some distancebeyond opposite sides of the intake conduit 32- as shown in Figure l.

The upper portion of the cylinder section -2 is provided with a'pair ofvalve chambers -33- and -33- located at opposite sides of the intakeconduit -32-, the valve chamber -38 being connected by a passage .34- tothe adjacent end of the upper portion of the piston chamber 7* and is-also connected by Aa port *B5- to the adj a- -cent end of 'theairiintake chamber -30-.

The other valve chamber -33- is connected by apassage -34lto the upperportion of the corresponding end of the piston lchamber -7- and is alsoconnected by a port -35- to the adjacent end of the air intake chamber-30-. Y

These ports --and -35- are respectively controlled by ball valves @5*and -Z)-, normaly seated in the upper portions thereof by theirownweig'ht and'therefore are `self-closing but adapted to be openedv bythe circulation of kair caused by the movements of the piston -12- in amanner presently described.

These valves also control communication between the Vair intake chamber30- and passages 84- and -34- respectively through the medium of theports 35- and -35- and are held against undue upward displacement by capportions -36 and -36-- which are releasably secured in openings in upperportions of the valve chambers -83- and -33- to permit access to thevalves for repair or replacements when desired.

The lower wall of the lower air chamber 3lis provided with a reducedcylindrical opening connected by a pipe or conduit -37- to the externalatmosphere or to any other suitable place of exhaust. The chamber -3lconstitutes what may be termed the exhaust chamber and extends axiallysome distance beyond the opposite sides of the exhaust pipe -37-, theopposite ends of said chamber being respectively connected by ports -38-and -38- to separate exhaust passages -39- and -39- which in turn areconnected to corresponding ends of the .lower portionof the pistonchamber -7-as lshown Vin Figure 1.

The lower walls of the exhaust passages I 39 and -39- are provided withcleanout 'spaced from the bottom 'walls of the chambers a distancesomewhat less than the diameters of the valves to enable the liquid topass freely from the ports -38- and -SSQ to the outlet conduit -37 asVshown in Fig ures l and 2.

One of the upright side walls of each of the valve chambers -40- and l0is provided with an opening -l3 of size to .permit the insertion andremoval. of their respectiveV valves cfand therethrough, said openingsbeing normally closed by 'a cover plate 114- which is releasably securedto the valve case by bolts 4:5* or equivalent fastening means, Figuresl2 and 3.

Operation, n Assuming now that the gear train is in operation and thatthe piston has just been forced to its extreme outer position as shown1n Figure l, then as the piston-1s moved 1n- `wardly the ball valve-awill be opened by reason of the partial vacuum formed in the passage34.- and higher air pressure in the chamber -30, thus permitting theinflow of air from the conduit -32- through the port 35- and passage S4-into the outer end of the piston chamber, while at the same time theexhaust valve -b will remain closed by reason of the partial vacuumcreated in the passage 39? and higher air pressure in the exhaustchamber -31-.

During this inward stroke of the piston, the valve -awill be openedbythe comvpressedair inthe passage -39- by reason of the lower airpressure inV the exhaust Ychamber -3l-, therebyallowing the air to`escape from the piston chamber vthrough the passage -39- and open port38'- and thence out through the exhaust conduit m37-, while at the sametime the air compressed by the inward movement of the piston in thepassage -84 will cause the valve -b to remain closed by reason of thelower pressure in the intake chamber -30-.

The inlow of vair into the outer end of ,the

vpiston chamber and outflow of air from the inner end of said chamberwill continue during the entire inner stroke of the piston.

On the other hand, during the out-stroke of the piston, the valve -bwillbe opened to allow the air from the corresponding end of the pistonchamber to flow outwardly through the exhaust conduit -37- and theAopposite valve ur/ will remain closed while the valve will also beopened to allow air to enter the inner end of the piston chamber throughthe passage 3ythis latter condition existing during the entire outstroke of the piston.

Brieiiy stated, during the instroke of the piston the intake controllingvalve a and exhaust controlling valve -awill both be opened while theother valves Z5-- and will be closed, but during the outstroke of thepiston the intake valves and exhaust valves -ZJ- will be opened and theother valves -aand -awill be closed so that a substantially continuousstream of air will be drawn into opposite ends of the cylinder duringthe reverse strokes of the piston and at the same time the air drawninto the cylinder will be continuously exhausted therefrom through theexhaust pipe -37 thus constituting what may be termed a double actingvacuum pump.

During this reciprocal movement of the piston -l2- by means ot the gears-23-, -24-, Q5- and -26-- and the pitman -17- the balanced condition ofthe pump on its supporting frame reduces the vibration of said pump to aminimum and thereby assures accuracy of operation of the valves and atthe same time the action of the gears, crankshaft and pitman within theoil containing case and resultant splashing of the oil serves toautomatically lubricate all of the moving parts within said case,including the gland -6-.

It will be noted that by arranging the valve case in a verticalposition, all ot the ball-valves are self-closing by their own weightand that they are automatically opened in sequence in the orderdescribed by the varying air pressures above and below the same producedby the action of the piston.

element and a cylinder element releasably secured together end to end, apartition extending transversely across the meeting ends of saidelements and provided with a gland co-axial with the cylinder element, apiston reciprocally movable endwise in the cylinder element and providedwith a rod extended through said gland, power-oriven means including agear train in the gear-case element operatively connected t0 said rodfor reciprocating the piston, said cylinder being provided with airinlet and outlet passages and valves controlled by the movement of thepiston for controlling said passages.

2. A vacuum pump comprising agear-case, a cylinder having air inlet andoutlet passages, releasable means for securing said gear-case andcylinder together end to end, a partition extending transversely acrossthe meeting ends of the gear-case and cylinder and provided with aguide-way extending into the gear-case, a cross-head reciprocallymovable alongv said guideway, a piston in the cylinder operativelyconnected to the crosshead to receive motion therefrom for circulatingair through the inlet and outlet passages, and means including a trainof gears in the gear-case for operating the cross-head.

3. A vacuum pump comprising a gearcase and a cylinder secured togetherend to end, said cylinder having air inlet and outlet passages, a pistonreciprocally movable endwise in the cylinder for circulating air throughsaid passages, valves controlled by the circulation of air forcontrolling the passages,-and power-driven means including a train ofgears within the gear-case for reciprocating the piston, said gearshaving their axes disposed in one and the same plane, the

gear-case being divided alongsaid plane into opposed sections, one ofwhich is removable. In witnesswhereof I have hereunto set my hand this13th day of February, 1931.

THOMAS F. MOORE.

Furthermore, by making the gear-case with Y the gears and pitman thereinas one unit and the cylinder and valve-case with the piston and valvestherein as a separate unit in the manner shown and described, eitherunit may be detached from the other unit without disturbing thecontained parts mentioned by simply removing the bolts -3- anddisconnecting the pivotal pin -18-, the latter being accessible when thelid -29- is removed, vunder which conditions the cross-head 14- and itsguideways -15- would be removed with the case section -2-. See Figure l.

l. A vacuum pump comprising a gear-case

